Silencer for use in connection with internal-combustion engines



Sept; 25,1923. 1,468,895

R. G. ALLAN SILENCER FOR USE IN CONNECTION WITH INTERNAL COMBUSTION ENGINES Filed Nov. 15 1921 Iruverutan 12?. 6.AZ/I/am/ Patented Sept. 25, 1923.

UNITED STATES PATENT OFFICE.

SILENCER FOR USE IN CONNECTION WITH INTERNALCOMBUSTION ENGINES.

Application filed November 15, 1921. Serial No. 515,398.

T 0 all whom it may concern Be it known. that I, .RoNALn GoRooN ALLAN, subject of the Kin of Great Britain, residing at Fortitude valley, Brisbane, Queensland, Australia, have invented certain new and useful Improvements in Silencers for Use in Connection with Internal-Combustion Engines, of which the following is a Specification.

This invention relates to silencers for use in connection with internal combustion engines, the object being to provide a silencer which is effective in operation and which does not cause any back pressure. The ar- F rangement is such that, while the exhaust is silenced, the consumption of oil fuel in the engine is greatly reduced and saving in cost of running is, therefore, effected. Furthermore, by the use of my invention, the carbon is removed and the cylinder is kept in a clean condition.

In carrying out my'invention I provide a chamber, into the end of which the exhaust pipe is led the other end being open to atmosphere. Within this chamber I provide two or more diaphragms, preferably conically shaped, two or more of which are each fitted with a flap valve opening outward from the intake end of the chamber. A small pipe or pipes (placedpreferably at an angle) is or are fitted in the chamber between the dia-phragms.

I will now more fully describe my invention with the aid of the accompanying drawings, in which- Fig. 1 is a sectional elevation thereof.

7 Fig. 2 isa sectional elevation of an alternative arrangement.

In carrying out my invention in the form shown in Fig. 1 I provide a chamber A of similar shape and construction to those at present in use, and into the end of which the exhaust pipe B from the engine is led.

In this chamber A are provided tWo diaphragms C, C suitably placed therein. The exhaust is connected to the inlet D and the other end E of the cylinder A is open to atmosphere. These diaphragms C and C are preferably of conical shape, (the apex being towards the outlet E). In the form shown in Fig. 2, the first diaphragm C is preferably perforated and the diaphragms C C are each provided with a valve F, opening respectively towards the outlet E of the chamber A, although Imay 1n some cases use a valveF in all the diaphragms C, C G a The pipe G is preferably fitted at' an angle immediately behind the diaphragm C, and, as shown, leads towards the diaphragm C additional pipes G may be used.

The form of device shown in Fig. 2 is especially adapted for use on aeroplanes. In this case the cylinder A should preferably taper towards the rear, and the leading end should be fitted with a conical or other suitably shaped nose H.

The details of construction may be varied as desired. It is to be understoodthat the three diaphragms C, C C shown in Fig. 2 may be used with parallel sided chambers A instead of the tapered sided chambers shown in that figure and the two diaphragms C, G shown in Fig. 1 may be used with tapered sided chambers A instead of the parallel sided chambers shown in that figure.

The operation of my invention is as follows When the puff of exhaust gases first reaches the chamber in which the pipe is situated, these gases have considerable velocity, suificient to force open all the check valves and also to cause some of the gases"- to be expelled through the pipe G. Almost instantly, however, as the gases expand, they are cooled in the chamber between the diaphragms, losing their pressure very quickly after being so cooled, with the result that air is forced in through a. small pipe by the atmospheric pressure outside the chamber and this cool air still further aids in almost instantaneously condensing the gases in the chamber, lowering still more the pressure. This action occurs particularly in the first discharge of the exhaust when the engine is started up. As the next puff of exhaust gases is projected into the chamber, the very hot gases meetthe cool air which has been drawn into the chamber and although the pressure may momentarily rise somewhat and for an instant the gases be forced out through pipe G and valves F, the pressure instantly again rapidly drops and the tendency is for more cool air to be forced in through the small pipe G.

This action may be observed by loosely holding a piece of paper over the mouth of the pipe G.

When the silencer is fitted with a perforated conical diaphragm C the exhaust gases would be broken up when passing through the perforations.

Having now particularly described and ascertained the nature of my said invention and in .what'manner the same is to be per formed I declare that what I claim is 1. -In an improvedsilencer for use in connection with internal combustion engines, a chamber having a plurality of diaphragms across it, each diaphragm having a port, check valves seated over said ports and opening in the direction of flow of gases through the chamber, said chamber having means between the diaphragms for permitting cooling and condensation of the hot gases in the chamber.

2; In an improved silencer for use in connection with an internal combustion engine, a chamber, a plurality of diaphragms arranged across said chamber, each having an opening and a check valve to cover said opening, the valves opening in the direction of flow of gases through said chamber, said chamber having an opening in its side be tween said diaphragms as and for the purposes set forth.

3. In an improved silencer for use in connection with an internal combustion engine, a chamber, a plurality of diaphragms arranged across said chamber each having an opening therein, check valves on said diaphragm openings, said check valves opening in the direction of flow of gases through said chamber, a pipe leading at an angle into the side of said chamber between said diaphragms, an exhaust pipe leading into said chamber, a tapered nose between the end ofthe chamber and exhaust pipe, and an outlet from said chamber as and 'for the purposes set forth.

4. In an improved silencer for use in connection with internal combustion engines, a chamber, a plurality of diaphragms arranged in said chamber, each having an opening therethrough, a check valve on each opening in the diaphragm, said check valves opening in the direction of flow of gases through said chamber, a dia hragm between said first mentioned diap ragms and the gas entrance, a perforation in said last mentioned diaphragm, a pipe leading at an angle into said chamber between each two of said diaphragms, an exhaust pipe from the engine leading into said chamber, an outlet at the other end of said chamber as and for the purpose set forth.

In testimony whereof I afiix my signature in the presence of two witnesses.

RONALD GORDON ALLAN.

Witnesses:

MABEL G. Low, ALEXANDER ANnnnsoN. 

